London | 26-ITP-Jan | Johnny Vargas | Sprint 1 | Coursework

Sprint-1/1-key-exercises/1-count.js

@@ -4,3 +4,6 @@ count = count + 1;
 
 // Line 1 is a variable declaration, creating the count variable with an initial value of 0
 // Describe what line 3 is doing, in particular focus on what = is doing
+
+// Line 3 is having the computer update the current "count" which is 0, with a "+ 1."
+// So now the current count becomes 1.

Sprint-1/1-key-exercises/2-initials.js

@@ -5,7 +5,8 @@ let lastName = "Johnson";
 // Declare a variable called initials that stores the first character of each string.
 // This should produce the string "CKJ", but you must not write the characters C, K, or J in the code of your solution.
 
-let initials = ``;
+let initials = firstName[0] + middleName[0] + lastName[0];
 
 // https://www.google.com/search?q=get+first+character+of+string+mdn
 
+console.log(initials);

Sprint-1/1-key-exercises/3-paths.js

@@ -17,7 +17,10 @@ console.log(`The base part of ${filePath} is ${base}`);
 // Create a variable to store the dir part of the filePath variable
 // Create a variable to store the ext part of the variable
 
-const dir = ;
-const ext = ;
+const dir = filePath.slice(0, lastSlashIndex);
+const ext = filePath.slice(filePath.lastIndexOf("."));
 
-// https://www.google.com/search?q=slice+mdn
+// https://www.google.com/search?q=slice+mdn
+
+console.log(dir)
+console.log(ext)

Sprint-1/1-key-exercises/4-random.js

@@ -7,3 +7,11 @@ const num = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;
 // Try breaking down the expression and using documentation to explain what it means
 // It will help to think about the order in which expressions are evaluated
 // Try logging the value of num and running the program several times to build an idea of what the program is doing
+
+
+// This code generates a random whole number between 1 and 100.
+// It starts with a random decimal, multiplies it to get the right range, and chops off the decimals to make it a whole number.
+// Then it adds the minimum to make sure the count starts at 1.
+
+
+console.log("The magic number is: " + num);

Sprint-1/2-mandatory-errors/0.js

@@ -1,2 +1,4 @@
-This is just an instruction for the first activity - but it is just for human consumption
-We don't want the computer to run these 2 lines - how can we solve this problem?
+// This is just an instruction for the first activity - but it is just for human consumption
+// We don't want the computer to run these 2 lines - how can we solve this problem?
+
+// We can comment it out by using "//"

Sprint-1/2-mandatory-errors/1.js

@@ -2,3 +2,8 @@
 
 const age = 33;
 age = age + 1;
+
+
+// The error "Assignment to constant variable" occurs because const is used to declare a constant value that cannot be changed.
+// Since the code tries to reassign the value on line 4 (age = age + 1), the program crashes.
+// To fix this, we would use let, which allows for variable reassignment.

Sprint-1/2-mandatory-errors/2.js

@@ -3,3 +3,7 @@
 
 console.log(`I was born in ${cityOfBirth}`);
 const cityOfBirth = "Bolton";
+
+
+// The 'ReferenceError' occurs because the code tries to use the variable cityOfBirth before it has been defined.
+// JavaScript reads from top to bottom, so the variable must be declared BEFORE it is called in the console.log.

Sprint-1/2-mandatory-errors/3.js

@@ -1,9 +1,15 @@
 const cardNumber = 4533787178994213;
-const last4Digits = cardNumber.slice(-4);
+const last4Digits = cardNumber.toString().slice(-4);
 
 // The last4Digits variable should store the last 4 digits of cardNumber
 // However, the code isn't working
 // Before running the code, make and explain a prediction about why the code won't work
 // Then run the code and see what error it gives.
 // Consider: Why does it give this error? Is this what I predicted? If not, what's different?
 // Then try updating the expression last4Digits is assigned to, in order to get the correct value
+
+
+// I predict an error will happen because cardNumber is a number and not a string and slice can not be used for pure numbers.
+// We can fix it by turning the number into a string by using .toString() before we slice it.
+
+console.log("The last four digits are: " + last4Digits);

Sprint-1/2-mandatory-errors/4.js

@@ -1,2 +1,8 @@
-const 12HourClockTime = "20:53";
-const 24hourClockTime = "08:53";
+const hourClockTime12 = "20:53";
+const hourClockTime24 = "08:53";
+
+// In JavaScript, variable names aren't allowed to start with a number.
+// The computer gets confused because it thinks 12 is a value, not a name.
+// To fix it, we have to start the name with a letter, like clockTime12Hour or just twelveHourClockTime.
+
+console.log(hourClockTime12 + " | " + hourClockTime24);

Sprint-1/3-mandatory-interpret/1-percentage-change.js

@@ -12,11 +12,19 @@ console.log(`The percentage change is ${percentageChange}`);
 // Read the code and then answer the questions below
 
 // a) How many function calls are there in this file? Write down all the lines where a function call is made
+// 4, 5, 10.
 
 // b) Run the code and identify the line where the error is coming from - why is this error occurring? How can you fix this problem?
+// It is coming from line 5. Because ("," "") is missing a comma separating the strings.
 
 // c) Identify all the lines that are variable reassignment statements
+// 4, 5.
 
 // d) Identify all the lines that are variable declarations
+// 1, 2, 7 , 8.
 
 // e) Describe what the expression Number(carPrice.replaceAll(",","")) is doing - what is the purpose of this expression?
+// JavaScript can't do math with commas.
+// replaceAll(",", "") part finds the , in "10,000" and turns it into nothing "", turning the String into "10000".
+// Even without the comma, it's still a String (text). The number part converts the text "10000" into the actual Number 10000.
+// The purpose is so it turns a string of numbers into actual numbers to do math with.

Sprint-1/3-mandatory-interpret/2-time-format.js

@@ -12,14 +12,23 @@ console.log(result);
 // For the piece of code above, read the code and then answer the following questions
 
 // a) How many variable declarations are there in this program?
+// There are 6. (6 Const in this case)
 
 // b) How many function calls are there?
+// 1, the last console.log(result)
 
 // c) Using documentation, explain what the expression movieLength % 60 represents
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Arithmetic_Operators
+// movieLength % 60 represents the seconds/minutes left over after you divide the total seconds/minutes by 60
 
 // d) Interpret line 4, what does the expression assigned to totalMinutes mean?
+// This expression calculates the total number of whole minutes in the movie.
+// It subtracts the "leftover" seconds so you have a number perfectly divisible by 60.
+// It divides by 60 to convert seconds into minutes.
 
 // e) What do you think the variable result represents? Can you think of a better name for this variable?
+// The variable result represents the formatted time string in HH:MM:SS (Hours:Minutes:Seconds) format.
+// A better name for it could be movieLengthFormatted.
 
 // f) Try experimenting with different values of movieLength. Will this code work for all values of movieLength? Explain your answer
+// If the seconds are a single digit like "5", the result will look something like 2:26:5. It makes it look unprofessional compared to say 02:26:05.

Sprint-1/3-mandatory-interpret/3-to-pounds.js

@@ -1,4 +1,4 @@
-const penceString = "399p";
+const penceString = "104569p";
 
 const penceStringWithoutTrailingP = penceString.substring(
   0,
@@ -25,3 +25,8 @@ console.log(`£${pounds}.${pence}`);
 
 // To begin, we can start with
 // 1. const penceString = "399p": initialises a string variable with the value "399p"
+// 2. const penceStringWithoutTrailingP = penceString.substring(0, penceString.length - 1): Removes the "p" from the end.
+// 3. const paddedPenceNumberString = penceStringWithoutTrailingP.padStart(3, "0"): Makes the string at least 3 letters long by adding "0"s to the front.
+// 4. const pounds = paddedPenceNumberString.substring(0, paddedPenceNumberString.length - 2): Grabs everything except the last two digits to find the "pound" amount.
+// 5. const pence = paddedPenceNumberString.substring(paddedPenceNumberString.length - 2).padEnd(2, "0"): Grabs exactly the last two digits.
+// 6. console.log(`£${pounds}.${pence}`): Combines the pounds and pence with a decimal point and a "£" symbol.

Sprint-1/4-stretch-explore/chrome.md

@@ -12,7 +12,14 @@ invoke the function `alert` with an input string of `"Hello world!"`;
 
 What effect does calling the `alert` function have?
 
+- It pops up an alert box with the text Hello world! in it.
+- I want to specify this did not work until I formatted it as "alert("Hello world!")
+
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
 
 What effect does calling the `prompt` function have?
 What is the return value of `prompt`?
+
+- Calling "prompt" brings up a box for me to insert text.
+- The return value of "prompt" is whatever was inserted in the box.
+- I input "let myName = prompt("What is your name?")" so it could store the name used. 

Sprint-1/4-stretch-explore/objects.md

@@ -6,11 +6,20 @@ Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
 
+- I get "ƒ log() { [native code] }"
+
 Now enter just `console` in the Console, what output do you get back?
 
+- I get "console {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …}"
+
 Try also entering `typeof console`
 
+- I get "'object'"
+
 Answer the following questions:
 
 What does `console` store?
+- Console stores various data, like "debug", "error", "info", "log" & "warn"
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+- The "." means for it to look inside for information using the tool written on the right.